Superworm – Fish Food Guide – Size & Appearance + Care

For so many years, superworms have been used to feed a number of tank animals including fish and turtles. Superworm is scientifically referred to as Zophobas morio, they have a unique life cycle too.

Superworm Facts

In their larval stage, they become large darkling beetle. At this stage of development, it is easy to confuse them with mealworm darkling beetle.

They are known to bite so hard. When giving them to pet animals, it may be necessary to crush their heads first, otherwise they may harm an animal, more so the young naive ones.

Human beings have been able to consume them too. Those who tasted superworms say they have an almond like kind of taste.

Size and Appearance


Superworms grow to a size of 50mm when mature. For them to sufficiently feed the pet animal, superworms need to be well fed and watered. If kept in large groups, it takes a long time for them to leave the larval stage. While in this form of their development, they often eat a great deal. If nothing is provided to them, they end up devouring their very own. For this reason, they are referred to as cannibals.

Known to feed mostly on dead and decaying vegetation, superworms can molt a number of times in their larval stage of development. This happens before they finally form a pupa. As soon as this happens, they emerge from their position completely white. With time, they gradually darken to turn into a black color. Not to forget is the fact that during their molting stage, superworms are easy to eat since they are softer.

They rarely inhabit the wild. In fact, they are generally found in storage areas particularly for grains. Barns are another area they are likely to be found in.

Superworm Life Cycle

The life cycle of superworm is the same as the rest of the other beetles. However, they tend to remain in their larval stage longer. In fact, they can take several months. The superworm undergoes a complete metamorphosis.

Mating Stage

During their mating season, the male transfers sperms to all the female eggs within her. The fertilized eggs remain within the female’s system in a specialized organ. Unlike most small animals, it goes through internal fertilization for reproduction.

Laying Eggs Stage

The female lays mature eggs in hidden places. This can be the bark of a rotting tree stump, in animal carcass, under decomposing vegetation or under soil with considerable humus. These eggs are whitish and very small. After laying eggs, the female leaves them there to hatch. It takes several days before this happens. When finally they hatch, the young worms crawl from the eggs to begin a life outside the tiny shells.

The Larval Stage

As previously said, they spend a long period of their lives in the larval stage. During this time, they have fully developed their three pair of legs and all mouth parts. This helps in their food hunt. In the wild, they eat anything from leaves, rotting bark of trees to decaying vegetation. In captivity, they can be fed vegetables and fruit remnants.

During their growth, they shed off their outer shell. This can happen several times during this stage. At this point in their development, they may remain in this stage as a large group unless they are isolated.

From the larval stage, they move to the pupal stage

The Pupa Stage

When ready for the pupal stage, they curl inwards from their heads to the tail. This helps them develop cocoons from silk. It hardens to be a protective shell. In the wild, they get their pupal grub from the soil. As they pupate, they are unable to move or even feed.

While inside the cocoon, the tissue found within the larva breaks down to form needed organs by the adult beetle.

Superworm Beetle Stage

It takes approximately 14 days from the larva to transform into pupa. After two weeks, the pupa changes to an adult beetle. As a beetle, the superworm will have developed legs, wings, antennae and all its reproductive systems.

As an adult, the beetle takes the same food as it did during its larval stage. They prefer dark places that are also damp and cool more so when the weather is humid. During their adulthood, they can live to about 15 years.

Superworm Care


Superworms are best suited for enclosures with proper ventilation. Sufficient Space is important to them too. They rarely climb out of their cage unless there is some form of interference. To avoid this, it is necessary to cover the enclosure.

When being housed, it pays to stock just a few in one enclosure. For a bigger number, a bigger space becomes a necessity but this could easily lead to cannibalism as the most aggressive feeders may pounce on the rest.

An aquarium with a capacity of 10 gallons is ideal for the superworm. If this is not available, a hobbyist could as well use a sizeable plastic tub with a good cover. The cover of the tub needs a hole that is covered with either a suitable wire mesh or screen. This is to provide ventilation as they can perish without the presence of fresh air. Word of caution; superworms cannot survive under refrigeration. So do not stock them in the fridge for whatever reason.


Naturally, they live in areas with dead wood or other types of decaying vegetation. While here, their beddings also become feeds. In the tank, the superworm can be offered powdered grain mixture. It will act as a bedding while doubling as food.

Mixtures acting as their feeds can be obtained through various ways. They can be bought as chick mash. They can also be made at home by blending a variety of grains together.

As they eat away at their food, they leave droppings (frass) in their wake. They also shed their skin. The two (frass and shed skin) are very fine and should replace powdered grain.


Superworms stay healthy when properly hydrated. Fruits and vegetables are a good source for this. Carrots, potatoes and fresh bananas can be very ideal. Vegetables to consider for them include broccoli stem, cabbage leaves, eggplant peels and cauliflower leaves. From their feeds, they obtain beta carotene. When the superworms are eventually fed to fish or other animals, they provide these nutrients to them.

During feeding, ensure that vegetable and fruit remnants are removed when they dry up to add fresh ones. It is important to avoid placing feeds that can rot into their habitat. If this happens, molds may get into the tank and this interferes with their bedding. Apart from the bad stench left behind, the superworms get quite uncomfortable and may eventually die.

Superworm is a great way to feed most tank animals especially bigger fishes like arowana and freshwater puffer fish.

Where to get them?

Due to the fact that superworms have become a mainstream staple for most pet animal, it can be bought at most pet stores. But for convenient sake, you can even get them via Amazon. Click mealworm darkling beetle to get some on Amazon.

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